# The Speed of Light is Not Constant

Discussion in 'Alternative Theories' started by Farsight, Feb 23, 2014.

1. ### Manifold1BannedBanned

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181

Which has been elaborated how, outside of arrogant attacks and ad hominems?

Or maybe you'll resort back to language capacities, since it seems like a good way to divert attention from any lack of knowledge on your behalf.

3. ### Farsight

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No I do not. You claim they're out of context to support your objective, which is to dismiss what Einstein said, or what Laughlin said, et cetera.

"It is ironic that Einstein's most creative work, the general theory of relativity, should boil down to conceptualizing space as a medium when his original premise [in special relativity] was that no such medium existed [..] The word 'ether' has extremely negative connotations in theoretical physics because of its past association with opposition to relativity. This is unfortunate because, stripped of these connotations, it rather nicely captures the way most physicists actually think about the vacuum..."

Don't give me "seems", because I know all about that. And that you're talking out of your hat. See for example this:

"In 1916, after Einstein completed his foundational work on general relativity, Lorentz wrote a letter to him in which he speculated that within general relativity the aether was re-introduced. In his response Einstein wrote that one can actually speak about a "new aether", but one may not speak of motion in relation to that aether. This was further elaborated by Einstein in some semi-popular articles (1918, 1920, 1924, 1930)..."

One of them was his 1920 Leyden Address. Note that "medium" is in there ten times. And note this:

"Recapitulating, we may say that according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an ether."

Suggests? Most of what I've read is there in black and white.

I haven't quoted him out of context, and nor have I misrepresented his intent.

5. ### Farsight

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Manifold1: please do not feed the troll.

7. ### OnlyMeValued Senior Member

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It is not what is in black and white that is an issue. It is how you interpret and sometimes misinterpret.., and then go on to insist that anyone who does not agree with your beliefs, does not understand physics. The problem with that, is that in many instances your interpretations are opposed to the consensus perspective among modern theorists, and the conclusions drawn from experimental data, by those conducting the experiments.

Make special note, that we are talking for the most part about the conceptual projection of what remains largely theory.., and what seems here to be a consensus that your position(s) are at odds with the mainstream.

You gain nothing by presenting your beliefs, ideas and conclusions, as infallible and absolute, while rejecting and walking on the mainstream consensus. No one person can lead the way forward. Progress in science comes only as the whole move forward. IOW even if somewhere in your ranting there lies some truth, in your arrogance you lose the discussion, as no one will listen to anyone who begins by proclaiming that everyone else is wrong!

8. ### Aqueous Idflat Earth skepticValued Senior Member

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As I stated in the technical content of my post, which you are ignoring since you never took either Physics I nor Calculus I, understanding reference frames requires understanding differential calculus. That's the fact Farsight denies here.

9. ### Aqueous Idflat Earth skepticValued Senior Member

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Spoeaking of trolling, when are you going to fix the gif you keep using which you admitted more than once is screwed up.

10. ### Aqueous Idflat Earth skepticValued Senior Member

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Aha. So Reiku and Rajesh are sock puppets of one another.

Don't blame me for your academic failures. If you'd taken the SAT you would have understood that academic competency is measured both in terms of verbal and math skills.

11. ### Farsight

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3,492
I give you the evidence and the references and the quotes, all parcelled together in a convincing argument within the OP. I just don't get anything similar in return. There's no evidence that you've even read the OP. No counterargument, no carefully crafted rebuttal, just denial and dismissal. And not just some point blank dismissal of what I've said, but point blank dismissal of what Baez / Wright / Magueijo / Moffat / Einstein said too

See above. See those names? Your "consensus" is a fantasy. There is no consensus. Instead those modern theorists who tell you the speed of light is absolutely constant are wrong. Don't you get it yet? For scientific progress to occur, what you think of as a consensus is a) shown to be not a consensus and/or b) shown to be wrong.

You're making it up as you go along. The experiments are things like the Shapiro delay. Irwin Shapiro concluded that light slowed down near the Sun.

You're kidding yourself that your view is right and it's mainstream. It isn't. Go and read the Don Koks article. That's the mainstream view. Amongst people who understand relativity rather than popscience quacks and mathematical theorists who have merely skimmed it whilst doing their PhD.

Ranting? Me? I give the evidence and the references, I don't rant. People who dismiss it rant.

There is total truth. And I am winning the discussion. Your arrogance loses you the discussion. Look at you, reduced to defending your untenable position by accusing me of something I haven't done. Bah.

12. ### Aqueous Idflat Earth skepticValued Senior Member

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:roflmao:

Yeah, with yourself. Since you can't answer even the high school level questions I posted . . . what recourse do you have but to preen in front of the mirror?

:shrug:

I write the songs / I write the songs

Evidence and the references? Yes. Evidence that you never studied the material. References? Sure, to material you can't understand, since it requires at least a freshman level of math and science competency. That's why it's so hilarious to watch you stumbling around, pretending to be Napoleon.

What is a field? What is a reference frame? What is the difference between light speed and coordinate speed of light? What is . . .

So many questions, such little time. What is it -- 10 years now? 12?
:roflmao:

Still waiting for the answers, Einstein

13. ### PhysBangValued Senior Member

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2,422
All those people say that the speed of light is constant at the level of local points in the manifold. You deny this. So you have a clear difference between your theory and existing physics. Existing physics uses the constancy of the speed of light in its equations. What do you use in your equations?

Please show us a single modern theorist who says that "the speed of light is absolutely constant".
One thing you have done is claim that Farsight-Relativity shows that the calculations for galaxy rotation curves is incorrect. Yet you haven't shown us the Farsight-Relativity derivation for this. Can you please show us?

14. ### przyksquishyValued Senior Member

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Huh? I'm sure that what PhysBang appreciates is what everyone who has learned GR appreciates: the gravitational pseudo-acceleration, in a fixed coordinate system, is given by the right-hand side of the geodesic equation if you arrange it as

$\frac{\mathrm{d}^{2} x^{\rho}}{\mathrm{d}\lambda^{2}} \,=\, - \Gamma^{\rho}_{\mu\nu} \, \frac{\mathrm{d}x^{\mu}}{\mathrm{d}\lambda} \, \frac{\mathrm{d}x^{\nu}}{\mathrm{d}\lambda} \,,$​

with the Christoffel symbols in turn given in terms of the metric component gradients by

$\Gamma^{\rho}_{\mu\nu} \,=\, \frac{1}{2} g^{\rho \kappa} \bigl[ \partial_{\mu} g_{\kappa\nu} \,+\, \partial_{\nu} g_{\mu\kappa} \,-\, \partial_{\kappa} g_{\mu\nu} \bigr] \,.$​

So that makes the pseudo-acceleration a function of: 1) the metric components, 2) their first coordinate derivatives, and 3) the components of the four-velocity of whatever it is you might be calculating the acceleration of.

Again: huh? Expanded in a fixed coordinate system, the Riemann tensor is quite a complicated function of the metric components and both their first and second coordinate derivatives.

Why? In Riemannian geometry, that's what a geodesic trajectory is, and this is the type of trajectory that light rays and test particles follow.

That's not accurate. It's true that.light will generally "curve" in coordinate systems in which the metric components are inhomogeneous, but the metric components are coordinate-system-dependent and inhomogeneous metric components is not synonymous with inhomogeneous space. For example, Riemann-flat spacetime is homogeneous, but the metric components associated with an accelerating reference frame in Riemann-flat spacetime are not, and light will typically bend in an accelerating reference frame even though the space is homogeneous.

The "gravitational potential" discussed on that Wikipedia page is a quantity from Newtonian gravity. It's not a fundamental quantity in GR at all. Why are you linking to it? In GR, you will generally only see the Newtonian potential appear in the weak field approximation, where GR approximately reduces to Newtonian gravity.

No it's not. Where are you getting this from? First, the plot you've linked to isn't much more than an "artist's impression" that gets tossed around usually alongside pop science explanations of GR. There's no explanation of what it is actually a plot of, and I doubt it's specifically meant as a plot of anything at all.

Second, as I mentioned above, the Riemann curvature is a function of the metric components and their first and second coordinate derivatives in a specific coordinate system, and it is only in the weak field approximation that you might see it expressed as a function of the Newtonian potential and its derivatives. Generally, there are ten independent metric components in a fixed coordinate system, and 20 independent components for the Riemann curvature tensor. Neither tensor generally lends itself to a simple plot.

15. ### Aqueous Idflat Earth skepticValued Senior Member

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Pot calling the kettle black. Koks:

To state that the speed of light is independent of the velocity of the observer is very counterintuitive. Some people even refuse to accept this as a logically consistent possibility, but in 1905 Einstein was able to show that it is perfectly consistent if you are prepared to give up assumptions about the absolute nature of space and time.

Sounds like Koks has met a lot of Farsights.

No it's the universally accepted view among all qualified experts. That is, there is no alternative theory. You are insinuating junk science into alternative theory, which is plausible under a given scenario. No scenario exists in which your nonsense is plausible. Only the one in which nobody gets an education, and instead sit around a campfire listening to you spin endless yarns about how wonderful you are.

Meaning the Farsights of the world: people who didn't major in math or science in college. Oh, sorry, that's improperly cast: Farsight evidently never made it to college.

:roflmao:

Let them eat cake, those pesky PhD candidates. And their advisors! Grrr!

A blight upon all things Farsight: absolute reference frames, physics without derivatives, light speed / coordinate speed equivalence, and of course the decomposition of relativity into a Lorentz rotation that acts only on time and not space:

which, if the PhD candidates will note, turns on the ability to defend one's dissertation with the all-encompassing caveat:

:roflmao:

16. ### OnlyMeValued Senior Member

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I am not entering into a line by line debate. Most of what you have said above has been addressed by others throughout this thread.

Here you have resorted to simply dropping names as if your interpretation of the intent of those individuals has not been and cannot be questioned.

And then you offer the Shapiro Delay as an experimental example, which even setting aside what you believe it demonstrates, only proves you have no idea of what the difference between theory and fact is. The Shapiro Delay is a subjective interpretation of distant events. Not an objectively controlled experiment... What the data reveals is entirely dependent upon the theoretical basis one uses to interpret it. It seems to me the consensus of those here, along with both Newton and Einstein, that it is the path of light through a gravity well (the velocity of light), not a variation in the speed of light, that best explains the data.

Again, I read most of what you present, as your belief based interpretations, presented as if they were undisputed facts. The constant insistence that you are the expert and all who disagree are wrong, is a very weak arguement. Time and again, your interpretations have been challenged by more than just one and from what I gather, on more than just one discussion group.

17. ### Farsight

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3,492
What you mean is you're resorting to dismiss and denial because you can find no chinks in my argument and you can offer no counterargument.

FFS, do your own research. Start with the Shapiro Delay on Wikipedia and what do you find? This:

"In an article entitled Fourth Test of General Relativity, Shapiro et al. wrote [1]: The proposed experiment was designed to verify the prediction that the speed of propagation of a light ray decreases as it passes through a region of decreasing gravitational potential"

Go look in a mirror. Yours are the belief-based interpretations. You are clinging to conviction. I refer you to the experts, to the evidence, and to Einstein, but you cling to your ignorance. Yes, my interpretations have been challenged, but nowhere can you find a successful challenge. Because when it comes to gravity, I'm the expert round here. I'm the guy who can explain it.

18. ### Farsight

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3,492
No, he demonstrated the classic confusion wherein he equated the degree of curvature to the force of gravity. Don't try to protect him with a fancy show. The guy's a troll and he's dishonest.

And don't try to pretend that things are so complicated that mere mortals can never understand them. Or we are going to fall out.

A light ray doesn't "follow" a goedesic. It curves because the space it moves through has metrical properties that are neither homogeneous nor isotropic. When we plot them, we plot a curved slope. But were we to plot them for a very large body such that the curvature was not apparent, the slope would still be apparent, and so would a curvature of a ray of light.

The accelerating reference frame isn't something that exists in an objective sense. It is little more than "a constantly changing state of motion". Observers watching the accelerating observer will assert that the light doesn't actually bend, even though the accelerating observer claims it does. So you need to discount this example. You're left with light curving when space is inhomogeneous, even when there's no apparent curvature to this inhomogeneity.

I'm linking to it because it offers a simple depiction that shows the first and second derivative.

Wake up przyk. This depiction is the bowling ball analogy which is also shown on the Wiki Riemann curvature tensor article.

It's a plot of gravitational potential. Yes it's Newtonian, but Einstein referred to gravitational potential too.

The weak field approximation is good enough when we're talking about the Earth's gravitational field. You have read the gravity works like this OP haven't you?

19. ### PhysBangValued Senior Member

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2,422
Really? That's the best you can do while you are dodging the question of how to calculate a galaxy rotation curve?

Such a question is relevant because you claim that "inhomogeneous space" is the answer to the bending of light and the reason that all physicists make a mistake in calculating galaxy rotation curves.
If things aren't so complicated, then you should be able to stop dodging the question of how to calculate a galaxy rotation curve.

Wow that's a stupid statement.
So let's see you plot something. And you can stop dodging the question of how to calculate a galaxy rotation curve.

20. ### Aqueous Idflat Earth skepticValued Senior Member

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Oh yes we did:

Yes it's exaggerated, and yes the mirrors should be tilted back a little, and yes the light pulses should curve a little
:roflmao:

The calculated speed, when uncorrected for relativity. But of course you would need an education to comprehend what Shapiro was talking about. He wasn't assuming dropouts would quote-mine him to try to pretend they know something. Otherwise he would have devoted a chapter to teaching you what he was talking about. The educated folks don't need the tutorial since, if they didn't get it high school, they covered the basics freshman year, and went on to take the advanced courses explaining it further. Passed their tests, that is.

You mean a temporally warped mirror in an unwarped spaceframe ??
/roflmao/

You mean the conviction that velocity is the time derivative of position, and therefore the local reference frame is infinitesimal as rpenner noted, and for which you insulted him? Yes, folks, let's not get to tied down here to mathematical abstractions. There may be time when we really don't want the definition of velocity to stick. And that's Farsight's idea of independent thinking. Yep, there's a New Boss in the faculty of Math Town, and he's a-gunnin' fer the crotchety old city slickers with them there fancy big shot diploma thangs.

/roflmao/

...because I, Farsight, can't refer myself to them. When I do, they don't speak to me. At least not in plain English I larnt in that there school house on the prairie.

...like my warped-time, unwarped space GIF which I admit is kinda screwed up. But don't ask me to fix it !!

It's part of the proof !!

...who isn't fit to shine my shoes, since of course he got all that there fancy larnin that undid his sense of absolute reference frames and uncorrected calculated light speed = actual light speed, and derivatives that actual vanish the way differential elements do. ('course I don' rally know wut a diff'rential elumunt is anyways.)

:roflmao:

..of all the dumb cluck stuff that goes on at the Farsight's little school house on the prairie. Where we shoot from the hip, and make it up when we wanna. And why? 'Cuz we can, y'all. Heck, we even print our own diploma thangs, y'all.

:roflmao:

...except on every page of this thread. Averaging about 2-3 dozen. Oh wait: he's measuring "success" relativistically. Doh !! /headslap/ In a timewarped / unwarped space coordinate system. Which is absolute. And can be calculated without relativistic correction, yielding c' ≠ c !! Of course we know how to set them suckers equal, don't we.

:roflmao:

/BANG BANG BANG/ Dammit y'all, die. Hell! Who loaded blanks in this thing? Aw, shucks !! That was me !! Garsh, if I'd only stayed in school I might be packin real lead.

Yes, you are the only one who can explain why you never finished school. Otherwise you wouldn't be warping time and not space in your dumb cluck GIF.

Just brilliant, Einstein !!

/roflmao/

21. ### przyksquishyValued Senior Member

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I don't. How did you get from "quite complicated" to "so complicated that mere mortals can never understand them"? Mere mortals can and do understand complicated things all the time.

In a given coordinate system, the Riemann curvature tensor has 20 independent components which are functions of the metric components and both their first and second coordinate derivatives. That is a fact. Look it up. It is not "the second derivative of potential".

Then why did Einstein derive the geodesic equation no less than twice (in sections B.9 and C.13) in his 1916 paper?

Why are you citing an analogy?

It's not good enough if the goal is to understand GR. The weak field approximation is not GR.

22. ### river

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11,565
What though of Sagnac's Rotational Version of Michelson-Morley experiment

Which showed that the velocity of light sent in the direction of Earths rotation , spin , varied from the velocity of light sent against the rotation of Earth ?